Insulating structure.



F. W. HARRIS. INSULATING STRUCTURE.

APPLICATION FILED JAN.7,1911.

Patented Feb. 23, 1915.

INVENTOR AfiQRNEY N r... S S E N H w UNITED; s'rA'rEs Form w. nA'n rs, 0F WILKINSBURG, PENNsYLvANis, ASSIGNOR TO WESTINGHOUSE ELECTRIC AND MANUFACTURING GOMP'ANY, A conronArroN or PENNSYLVANIA.

INSULATING STRUCTURE.

Specification of Letters Patent.

Iatented Feb. 23, 1915.

Application filed January 7. 191 1. Serial No. 601,401.

To all whom it may concern le it known that 1, FORD W. HARRIS, a citizen of the United States, and a resident of Vilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Insulating Structures, of which the following is a specification.

My invention relates to insulating bodies for use with electric apparatus and it has special reference to such insulating sleeves or bushings as are utilized with very high.- voltage transformers and other electric devices inclosed in metal tanks or casings.

The object of my invention is to provide an insulating body of the aforesaid character. which shall be capable of sustaining or withstanding high voltage, relative to the amount of insulating material employed in its structure. and which, at the same time, shall be suitable for operation out of doors or under other adverse conditions.

In order to accomplish the aforesaid objective results, I utilize a bushing of the socalled condenser type, which is composed of alternate layers of insulating and conducting materials and is substantially cylindrical in form. The cylindrical insulator is surrounded by a close-fitting metal sleeve and its ends, which are tapered, are inclosed in segmental sleeves, prefer ably composed of a series of porcelain rings which are cemented together and to the metal sleeve.

The single figure of the accompanying drawings is a sectional elevation of an in sulating bushing constructed in accordance with my invention.

Referring to the drawing, a cylindrical bushing having a body 1, and gradually tapering ends 2 and 3 is entirely inclosed in a sleeve or jacket 4. The jacket & comprises a sleeve or bushing 5 which is preferably made of metal and fitted closely onto the cylindrical body 1 of the main bushing, a, plurality of rings or short sleeves 5 of porcelain or other similar insulating material, and metal caps 7. The-rings (3 and the sleeve 5 have coo crating beveled edges and are assembled en to end to constitute a hollow cylindrical jacket of substantially the same length as the main bushing. The parts of the sleeve or jacket are cemented together and are held in place by the caps 7 which are fitted onto the end rings. The caps are body of the drawn toward each other by a metal rod or bar 9 which extends entirely through the main bushing and is screw-tl'ireaded at its ends to receive binding nuts 8. The rod or bar Q may be replaced by a tube of suitable 'iaterial and constitutes a conducting lead. to'the respective ends of which electric line conductors may be connected.

The space within the sleeve l is filled with insulating gum or some other suitable air tight sealing compound in order to hermetically seal the exposed edges of the insulating and conducting layers of the main bushing and thereby render itfree from deterioration.

The main bushing itself is preferably of the condenser type and is built up of alternatt-vlayers l0 and 11 of insulating and conducting materials, as set forthin Patent No. 952,513, g nted March 22, 1910, to the Westingho .W Electric & liilanufacturing Company, on an application filed July 5,

1907, by James C. Eon".

ings that to be utilized for high voltage service, it may be economical to use cylindrical envelope for the tapered ends 2 and 3 ot the body 1, as shown in the drawing, because, in this manner, varying thicknesses of dielectric material may be disposed adjacent to otherwise exposed edges the several conducting layers of the bushing. The exposed edges of the conducting cylinders, which are of smallest diametcr and nearest to the electrical conductor to be insulated, are embedded in dielectrio material of suilicient thickness to prec corona discharges therefrom under c Jain In. sir-Quin potentials. At the same time, the edges of the remaining conducting layers also embedded dielectric material of adequate thickness. lln iew of the aforementioned insulating qualities and the ease of assembling and the low cost of supplying insulating rings 6 which are of ends and composed of alternate layers of insulating and conducting materials, a sleeve fitted upon the cylindrical portion of the body, insulating rings assembled end to end as extensions of the sleeve, metal caps for the outer rings and means for clamping the sleeve rings and caps together.

24 terminal bushing for electric circuits comprising a tubular body having tapered ends and a substantially cylindrical intermediate portion, a sleeve fitted upon'the cylindrical portion of the body,insulating rings assembled end to end around each tapered portion of said body metal end caps for the outer insulating rings and means for drawing the caps toward each other to hold the insulating rings in position.

3. An insulating bushing comprising a body having a substantially cylindrical portion and tapered ends and composed of alternate layers of insulating and conducting materials, a plurality of insulating rings superposed upon one another to constitute an envelop for each tapered end of said body, an insulating compound interposed between said rings and said body to seal hermetically the exposed edges of the insulating and conducting layers of the body, metal caps engaging the outer rings of each envelop, and means for clamping said rings and caps together.

4. An insulating bushing comprising a body having a substantially cylindrical portion and tapered ends and composed of alternate layers of insulating and conducting materials, a plurality of insulating rings of equal diameter superposed upon one another to constitute a cylindrical envelop for each tapered end of said body, an insulating compound interposed between said rings' and said body to seal hermetically the exposed edges of the insulating and conducting layers of the body, metal caps engaging the outer rings of each envelop, and means for clamping said rings and caps together.

In testimony whereof, I have hereunto subscribed my name this 3rd day of Jan.

FORD W. HARRIS. Witnesses:

VVILSON L. WRIGHT, B. B. HINES.

Copies of this patent may be obtained for five cents each, lay-addressing the Commisslonerjof Patents,

' Washington, D. C. 

